1. Field of the Invention
The present invention relates to a power generating device in which rotation of a main shaft by external force is increased in speed with speed up gears to drive a generator.
2. Description of the Related Art
The speed up gears are used for a wind power generating device in order that wind force is received with blades to rotate the main shaft that is connected to the blades and the rotation of the main shaft is increased in speed to drive the generator. As shown in FIG. 16, the speed up gears 202 include a planetary gear mechanism 203 that receives the rotation of a main shaft 200 to increase the speed, a high-speed gear mechanism 204 that receives the rotation of which the speed is increased by the planetary gear mechanism 203 and further increases the speed of the rotation, and an output shaft 205 that outputs running torque of the high-speed gear mechanism 204.
The planetary gear mechanism 203 is constructed such that when an input shaft 203a that is coupled to the main shaft 200 so as to be capable of rotating together rotates, a planet carrier 203b also rotates, and therefore a sun gear 203d rotates with increased speed through a planet gear 203c, and the rotation is transmitted to a low-speed shaft 204a of the high-speed gear mechanism 204. The high-speed gear mechanism 204 is constructed to rotate an intermediate shaft 204d with increased speed through the low-speed gear 204b and a first intermediate gear 204c when the low-speed shaft 204a rotates and further rotate the output shaft 205 with increased speed through a second intermediate gear 204e and a high-speed gear 204f. As respective bearings for rotatably supporting the low-speed shaft 204a, the intermediate shaft 204d, and the output shaft 205 of the speed up gears 202, roller bearings 206 to 211 are frequently used (see Japanese Patent Application Publication No. 2007-232186 (JP 2007-232186 A), for example).
In addition, a wind power generating device that receives wind force with blades to rotate the main shaft which is connected to the blades and increases the speed of the rotation of the main shaft to drive the generator is known. The speed up gears for increasing the rotation of the main shaft in speed includes, as shown in FIG. 16 for example, a planetary gear mechanism 203 that increases the speed of the rotation which is received from a main shaft 200, a high-speed gear mechanism 204 that further increases the speed of the rotation which is received from the planetary gear mechanism 203, and an output shaft 205 that outputs running torque of the high-speed gear mechanism 204. The output shaft 205 is coupled to a drive shaft of the generator (not shown) so as to be capable of transmitting drive power.
The planetary gear mechanism 203 is constructed such that when the rotation of the main shaft 200 is transmitted to the input shaft 203a, the planet carrier 203b rotates, and therefore the sun gear 203d rotates with increased speed through the planet gear 203c, and the rotation is transmitted to the low-speed shaft 204a of the high-speed gear mechanism 204. In addition, the high-speed gear mechanism 204 is constructed to rotate the intermediate shaft 204d with increased speed through the low-speed gear 204b and the first intermediate gear 204c when the rotation is transmitted from the planetary gear mechanism 203 to the low-speed shaft 204a rotates and further rotate the output shaft 205 with increased speed through the second intermediate gear 204e and the high-speed gear 204f. 
As respective bearings for rotatably supporting the low-speed shaft 204a, the intermediate shaft 204d, and the output shaft 205 of the speed up gears 202, roller bearings 206 to 211 are frequently used (see JP 2007-232186 A, for example).